JPH0510401A - Hypocycloidal reduction gear - Google Patents

Abstract

PURPOSE:To improve the torque transmission efficiency and shorten assembling time while reducing noise by revolving a first planetary gear interlockingly with an eccentric shaft part rotated in association with the rotation of a motor, and auto-rotating a second internal tooth gear by a second planetary gear fixed to the first planetary gear to fetch reduced rotating speed. CONSTITUTION:A first planetary gear 2 and a second planetary gear 4 are integrally formed, and the eccentric shaft part 50 of a shaft body 5 coaxial with a motor 9 is fittingly inserted into the center parts of both planetary gears 2, 4. The first planetary gear 2 and the toothed belt 11 of a first internal tooth gear 1 are assembled in the pre-load state to drive the first planetary gear 2. Accordingly, the second planetary gear 4 is also rotated together with the first planetary gear 2, and a second internal tooth gear 3 meshed with the second planetary gear 4 is rotated to drive a toothed belt 31. The reduced rotating speed can be thereby fetched by appropriately setting the number-of- teeth of the first internal tooth gear 1, first planetary gear 2, second planetary gear 4 and second internal tooth gear 3.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cyclo gear reducer, and more particularly to a hypocycloid gear reducer.

2. Description of the Related Art As a two-stage type of hypocycloid speed reducer, there is, for example, one including a first speed reducer A and a second speed reducer B as shown in FIG. The first
As shown in the figure, the reduction gear unit A has an annular first internal gear 1 (the number of teeth Z1) that is fixed coaxially with the rotation axis of the motor, and has a slightly smaller number of teeth than the first internal gear 1. First planetary gear 2
(Number of teeth Z2) and a first shaft body 5a having an eccentric shaft portion and coaxially fixed to the rotation shaft of the motor,
The first planetary gear 2 is revolved in such a manner that the first planetary gear 2 meshes with the first internal gear 1 in association with the movement of the eccentric shaft portion accompanying the rotation of the motor, and the rotation number of the first planetary gear 2 is changed to the first Oldham coupling 8
It is taken out as the first stage deceleration speed via 0. Second
The speed reducing portion B is attached to the output side of the first Oldham coupling 80, has an eccentric shaft portion, and has a second shaft body 5b that is coaxially fixed to the rotation shaft of the motor, and is coaxial with the rotation shaft of the motor. An annular second internal gear 3 (the number of teeth Z3) fixed above, and a second planetary gear 4 having a slightly smaller number of teeth than the second internal gear 3.
(The number of teeth Z4), the second planetary gear 4 is moved to the second planetary gear 4 in association with the movement of the eccentric shaft portion accompanying the rotation of the second shaft body 5b.
The second planetary gear 4 is revolved in the manner of meshing with the internal gear 3 and the rotation speed of the second planetary gear 4 is taken out as the second-stage deceleration rotation speed via the second Oldham coupling 81. The reduction ratio of this thing is
[(Z1-Z2) / Z2] × [(Z3-Z4) / Z4]
Therefore, as compared with a speed reducer that reduces the speed by engaging the outer teeth of a normal gear with each other, a large reduction ratio can be obtained even with a small size. However, the above-mentioned ones have a problem that a large noise is generated and the torque transmission efficiency is low because the Oldham joint has a sliding portion. Also, since the number of parts is large, it takes a lot of time to assemble and it is difficult to reduce the size.

SUMMARY OF THE INVENTION Therefore, the present invention provides a hypocycloid speed reducer which produces less noise, has high torque transmission efficiency, and can be downsized and the time required for assembly can be reduced. This is an issue.

In the hypocycloid speed reducer according to the first aspect of the present invention, an annular first internal gear fixed coaxially with the rotation shaft of the motor and a number of teeth slightly smaller than the first internal gear. Less and less in mesh with the first internal gear
A planetary gear, a second planetary gear having a smaller number of teeth than the first planetary gear and fixed coaxially with the first planetary gear, an eccentric shaft portion, and coaxially with the rotation shaft of the motor. A shaft body to be mounted and a second internal gear that is rotatably mounted on the shaft part other than the eccentric shaft part in a retaining state and is in mesh with the second planetary gear in this mounted state. A second planetary gear fixed to the first planetary gear, wherein the first planetary gear revolves in a manner to mesh with the first internal gear in association with the movement of the eccentric shaft portion accompanying the rotation of the motor. The second internal gear is rotated by the revolution of the gear, and the rotational speed of this second internal gear is taken out as the deceleration rotational speed. Further, in the invention according to claim 2, with respect to the invention according to claim 1, the meshing portion of the first internal gear with the first planetary gear and the meshing portion of the second internal gear with the second planetary gear are provided. , Made of elastic rubber material.

The present invention has the following actions. (Operation of the invention described in claim 1) The number of teeth of the first internal gear is Z1.
, The number of teeth of the first planetary gear to Z2, to the second internal gear Z3,
The deceleration action when the number of teeth of the second planetary gear is set to Z4 will be described. (1). The shaft is rotated as the motor rotates, and the eccentric shaft portion of the shaft moves to cause the first planetary gear to revolve in a manner to mesh with the first internal gear. And the first
While the planetary gear makes one inscribed revolution of the first internal gear, (Z1-
Z2) / Z2 will rotate. The second planetary gear is fixed to the first planetary gear coaxially therewith,
It revolves integrally with the first planetary gear and rotates (Z1-Z2) / Z2 during one revolution. (2). Next, the (Z1-Z2) / Z2 rotating second planetary gear is rotatably attached to the shaft portion other than the eccentric shaft portion in a retaining state, and in this attached state, Since the second internal gear is in mesh with the second internal gear, if the second internal gear revolves once, the second gear should rotate (Z1-Z3) / Z3 coaxially with the rotation axis of the motor. Becomes (3). That is, in the present invention, [(Z1-Z2) /
A reduction ratio of Z2] × [(Z1-Z3) / Z3] will be obtained. As described above, a large reduction ratio can be obtained even with the structure of the hypocycloid speed reducer of the present invention.
It has the following effects. ． Compared with the hypocycloid reducer described in the section of the prior art, since there are no two Oldham couplings, there is no unnecessary sliding part inside the reducer, and as a result, the generated noise is small and The torque transmission efficiency is high. ． Compared with the hypocycloid reducer described in the section of the prior art, one shaft does not exist in addition to the two Oldham couplings, so the number of parts is reduced as a whole, resulting in miniaturization and The time required for assembly can be shortened. (Operation of the invention according to claim 2) First in the first internal gear
Since the meshing portion with the planetary gear and the meshing portion with the second planetary gear in the second internal gear are made of elastic rubber material,
The tooth portion of the first internal gear follows the tooth portion of the revolving first planetary gear, and the tooth portion of the second internal gear follows the tooth portion of the revolving second planetary gear, and meshes while deforming. .
． Therefore, in the meshed state, the internal gears and the planetary gears mesh with each other with a large number of teeth without causing a large slip, and as a result, the generated noise is smaller than that of the invention according to claim 1. As a result, the torque transmission efficiency becomes high.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the drawings shown as embodiments. The hypocycloid speed reducer of this embodiment is a two-stage speed reducer, and as shown in FIGS. 1 to 3, an annular first internal gear 1 fixed coaxially with a rotating shaft 90 of a motor 9, and A first planetary gear 2 having a smaller number of teeth than the first internal gear 1 and in mesh with the first internal gear 1; and a first planetary gear 2 having a slightly smaller number of teeth than the first planetary gear 2. Second planetary gear 4 fixed coaxially with
A shaft body 5 which has an eccentric shaft portion 50 and is coaxially mounted on a rotating shaft 90 of a motor 9, and a shaft body 5 other than the eccentric shaft portion 50 which is rotatably mounted in a retaining state. In addition, it is composed of the second planetary gear 4 and the second internal gear 3 in mesh with each other in this mounted state (principle diagram is shown in FIG. 4). As shown in FIGS. 2 and 3, the first internal gear 1 has an elastic rubber material (material: chloroprene,
An annular toothed belt 11 made of urethane or the like)
And a substrate 10 to which the toothed belt 11 is attached. As shown in FIG. 8, the toothed belt 11 includes six core wires 12 (materials: glass fiber, Kevlar, etc.) embedded in the circumferential direction and a tooth cloth 1 attached to the tooth surface.
3 (material: nylon, polyester, etc.) and reinforcing cloth 12
In this embodiment, the number of belt teeth is 53. Further, the belt tooth profile has an H / W = 0.5 to 0.67, α = 18 ° to
Those corresponding to 23 °, 1 / W = 0.20 to 0.66, and R1 / W = 0.7 to 0.9 can be adopted. The substrate 10 is made of synthetic resin, and as shown in FIGS. 2 and 3, has a positioning hole 14 for positioning with the motor 9 in the center thereof and a pair of bolt holes 15 formed therein. Has been formed.
The first planetary gear 2 is made of synthetic resin and has 51 teeth, and its tooth profile is Hp / Wp = 0.47 to 0.64, αp = 18.5 ° in the explanatory view shown in FIG.
〜23.5 °, W / Wp = 0.95〜1.00, lp / Wp = 0.1〜
Those equivalent to 0.65 can be adopted. Further, as shown in FIGS. 2 and 3, the first planetary gear 2 is integrally molded with the second planetary gear 4, and the center of the integrally molded first and second planetary gears 2, 4 is formed. The eccentric shaft portion 5 of the shaft body 5 described above
A bearing 20 into which 0 is fitted is attached. Incidentally, the toothed belt 11 of the first planetary gear 2 and the first internal gear 1
And are designed to be in a pressure contact state (pre-loaded) in the assembled state, thereby improving the torque transmission efficiency. The second planetary gear 4 has 50 teeth and its tooth profile is Hp / Wp = 0.0 as shown in FIG.
47 to 0.64, αp = 18.5 ° to 23.5 °, W / Wp = 0.95 to 1.
Those corresponding to 00, lp / Wp = 0.1 to 0.65 can be adopted. As shown in FIGS. 2 and 3, the second internal gear 3 includes an annular toothed belt 31 made of an elastic rubber material (material: chloroprene, urethane, etc.), and the toothed belt 31.
And a circular substrate 30 to which is attached. As shown in FIG. 8, the toothed belt 31 includes six core wires 12 (material: glass fiber, Kevlar, etc.) embedded in the circumferential direction and a tooth cloth 33 (material: nylon, polyester) attached to the tooth surface. Etc.) and a reinforcing cloth 32a. In this embodiment, the number of belt teeth is 52. Further, the belt tooth profile is as follows: H / W = 0.5 to 0.67, α = 18 ° to 23 °, 1 / W =
Those corresponding to 0.20 to 0.66 and R1 / W = 0.7 to 0.9 can be adopted. The circular substrate 30 is made of synthetic resin and, as shown in FIGS. 2 and 3, has a toothed wheel portion 34 protruding from the center thereof and a bearing 35 attached thereto. In addition, the toothed belt 31 of the second internal gear 3 and the second planetary gear 4 are brought into a pressure contact state (pre-loaded) in an assembled state, thereby improving torque transmission efficiency. is there. The shaft body 5 has the eccentric shaft portion 50 as described above. As shown in FIG. 3, the shaft body 5 has a vibration preventing balance weight 52 at one end and a C-shaped pin 6 at the other end. A peripheral groove 53 is formed, and due to the presence of the enlarged diameter portion 52 of the shaft body 5 and the C-shaped pin 6, as shown in FIG. The gear 4 is set to be in a retaining state. Then, in this embodiment, as shown in FIGS. 2 and 3, the balance weight 70 is provided between the second internal gear 3 and the second planetary gear 4, whereby the shaft 5 The vibration of the speed reducer due to rotation is reduced. The relationship between the first internal gear 1 and the first planetary gear 2 is shown in FIG. 5, the relationship between the second internal gear 3 and the second internal gear 4 is shown in FIG. 6, and the motor 9 is attached to the reduction gear. Figure 7
, Respectively. Since the cycloid speed reducer of this embodiment has the above-described structure, the speed is reduced as described below. (1). With the rotation of the motor 9, the shaft body 5 is rotated,
By moving the eccentric shaft portion 50 of the shaft body 5, the first planetary gear 2
Are revolved in such a manner that they mesh with the first internal gear 1. Then, the first planetary gear 2 rotates (53−51) / 51 while the first internal gear 1 revolves inscribed one revolution. Since the second planetary gear 4 and the first planetary gear 2 are integrally formed, the second planetary gear 4 revolves integrally with the first planetary gear 2 and rotates (53-51) / 51 during one revolution. ing. (2). Next, the (53-51) / 51 rotating second planetary gear 4 is rotatably attached to a portion other than the eccentric shaft portion 50 of the shaft body 5 in a retaining state, and this attachment Since the second internal gear 3 is meshed with the second internal gear 3 in this state, when the second internal gear 3 revolves once, the second internal gear 3 is coaxial with the rotating shaft 90 of the motor 9 (53- 52) / 52 will be rotated. (3). That is, in the present invention, [(53-51) /
51] × [(53−52) / 52] = 1/1326 will be obtained. In the speed reducer described in the section of the prior art, when the number of teeth of each gear is the same as that of the above embodiment, [(53-51) / 51] ×
Only the reduction ratio of [(52-50) / 50] = 1 / 637.5 can be obtained, and it is understood that the reduction ratio of the present invention is high. As described above, a large reduction ratio can be obtained even with the structure of the hypocycloid speed reducer of this embodiment, and further, two Oldham couplings and one Since there are no two shafts, there is no useless sliding part inside the reducer, resulting in less noise and high torque transmission efficiency, which reduces the time required for downsizing and assembly. It will be possible to measure.

Since the present invention has the structure as described above, it has the following effects. As described in the section of the action, it is possible to provide a hypocycloid speed reducer capable of reducing the noise generated, having a high torque transmission efficiency, and reducing the size and the time required for assembly.

[Brief description of drawings]

FIG. 1 is a side view of a hypocycloid speed reducer of the present invention mounted on a motor.

FIG. 2 is a sectional perspective view of the hypocycloid speed reducer.

FIG. 3 is an exploded perspective view of the hypocycloid speed reducer.

FIG. 4 is a principle diagram of the hypocycloid speed reducer.

5 is a cross-sectional view taken along the line AA of FIG. 2, showing a relationship between a first internal gear and a first planetary gear in the hypocycloid speed reducer.

6 is a cross-sectional view taken along the line BB of FIG. 2, showing the relationship between the second internal gear and the second planetary gear in the hypocycloid speed reducer.

FIG. 7 is a view showing a mounting surface of the hypocycloid speed reducer with a motor.

FIG. 8 is a detailed view of a toothed belt forming first and second internal gears.

FIG. 9 is a view showing a tooth profile of a toothed belt that constitutes the first internal gear.

FIG. 10 is a view showing a tooth profile of the first planetary gear.

FIG. 11 is a view showing a tooth profile of a toothed belt which constitutes the second internal gear.

FIG. 12 is a view showing a tooth profile of the second planetary gear.

FIG. 13 is a principle diagram of a conventional two-stage hypocycloid speed reducer.

[Explanation of symbols]

1st internal gear 2 First planetary gear 3 Second internal gear 4 Second planetary gear 5 axis 50 Eccentric shaft

Claims (3)

[Claims] 1. An annular first internal gear fixed coaxially with a rotating shaft of a motor, and a first planetary gear having a number of teeth slightly smaller than that of the first internal gear and meshing with the first internal gear. Gears,
A second planetary gear having a smaller number of teeth than the first planetary gear and fixed coaxially with the first planetary gear, and a shaft body having an eccentric shaft portion and coaxially attached to the rotation shaft of the motor. And a second internal gear that is rotatably attached to a shaft portion other than the eccentric shaft portion in a retaining state and is in mesh with the second planetary gear in this attached state. , By revolving the second planetary gear fixed to the first planetary gear, by revolving the first planetary gear in a manner in which the first planetary gear meshes with the first internal gear in association with the movement of the eccentric shaft portion accompanying the rotation of the motor. A hypocycloid speed reducer characterized in that the second internal gear is rotated, and the rotational speed of the second internal gear is extracted as the deceleration rotational speed. 2. The meshing portion of the first internal gear with the first planetary gear and the meshing portion of the second internal gear with the second planetary gear are made of elastic rubber material. Item 1
The described hypocycloid reducer. 3. A meshing portion of the first internal gear with the first planetary gear and a meshing portion of the second internal gear with the second planetary gear are made of an elastic rubber material, and in the elastic rubber material. The hypocycloid speed reducer according to claim 1, wherein a core material extending in a circumferential direction is embedded.